The present invention relates to earth moving equipment, such as a motorized grader, and more particularly to systems controlling the position of a blade with respect to the ground on which the equipment travels.
During road construction, the earth is graded to a relatively smooth subsurface prior to laying asphalt or concrete which forms the surface of the road. The graded subsurface is produced by a machine that has a blade which scrapes the earth to a level desired for the subsurface.
A typical motorized road grader has the blade mounted between the front and rear wheels. Therefore, the front wheels ride on an uneven, ungraded surface ahead of the blade and the rear wheels ride on the smoother graded surface produced by the blade. As the front wheels move over undulations in the ungraded surface, the relative position of the blade changes, thereby producing an undulating graded surface. Thus the grader must make multiple passes over the area being graded until the surface has the desired degree of smoothness. Alternatively, the operator has to continuously make manual adjustments to the blade height, which requires a experienced operator and can produce operator fatigue.